Electric water heater



1.927'. April 12| T. H' MQQUINN mamme` WATER HEATER Filed April 27. 1925 Patented Apr. 12, 1927.

THOMAS HORACE HOQUINN, 0F PRESTON,

1,624,843 PATENT OFFICE.

uELaoUnNa, vic'roaia, a-Us'rnaua, as-

BIGNOR 0F TWO-.THIBDS T0 HARRY NORTON SABGOOD, 0F TOOBAX, VICTORIA,

AUSTRALIA.

ELECTRIC WATER HEATER.

Application led April 27, 1925, Serial 110.26385, and in Great Britain June 10, 1924.

` provide a Water heater comprising a hollow eating element which is arranged within an outer casing or casings of different diameters to thereby provide a water circulating passage having one branch extending longi- I tudinally through the heating element and one or more interconnected passa es surrounding `said heating element, t e said branch passages being of relativel small varea in cross section Whilst the heating surfaces of the heating element are relatively large. By this arrangement it is ensuredthat all the heat will 'be absorbed by the water, resulting in a maximum thermal eiciency and a practically instantaneous flow of hot water.

According to the invention the im roved heater comprises a tube or tubular e ement composed of a inaterialwhich is yheat i'efrac ory and a nonconductor ofelectricity, the said tube being wound, or otherwise suitably covered externally, withfa conducting wire or other form of electric resistance along which current may be passed from any suitable source of supply. The heating tube is preferably disposed concentri-v cally within two or more cylindrical casings of different diameters, the various parts being suitably connected at their ends so that 7the internal passage of the heating tube and tlie longitudinally extending annular space between the cylindrical casines communicate with each other at their ens and provide a continuous water circulating passage through which the water to be heated iiows and wherein it is continually subjected to the action of the heating tube.

, In some instances, in order to reduce the length of the tubular heating element neces sary to' obtain the results required, I may make use of two or more heating tubes of different diameters which may be fitted concentrically one within the other and each of them covered or externally wound with a resistance wire for the passage of the electric current. Cylindrical casings of various diameters are arranged concentrically bein Figure 1.

Figure '4 is a cross section on theline B-B of Figure 1.

In the accompanying drawings the numeral 2 is employed to indicate generally -fthe heating tube or tubular element .com-

osed of silica or other substance which is ieat refractory and a non-conductor of velectricity .and thi-ou hwhich the water to be' heated passes an 3 the resistance or conducting Wire which is preferably helically wound around the exterior of the said tube, for the passage of the heating current.

Eachheating tube may be provided externally with a spiral groove to form a seating for the resistance wire 3.

In the embodiment shown in Figures 1 to 4 a single heating tube 2 is arranged concentrically within inner and outer cylindricalcasings 4 and 6 of equal length, the

outer casing 6 being provided with an inlet opening 7-rom which a nipple 8 may outstand. The longitudinally extending annular space 9 formed between the two casings 4 and 6 constitutes a first or initial passage for the water to bel heated. End fittings are provided to retain the heating tube 2 and the casings 4 and 6 in proper relative position, so that no leakage of water is possible, and one of these end fittings is adapted to afford communication between the aforesaid annular space or initial water heating passage 9 and the internal passage 11 of the 100 heating tube as hereinafter described.

The end fittings may each comprise outer sectionsor caps 13 and 14 of metal or the like, and inner sections 16 and 17 which may be com osed of a suitable heat refractory materia and have their inner faces recessed as at 18 and 19 to furnish seatings for jointing rings or washers 21 and 22. These recessed faces also provide circular lips 23 against the inner and outer peripheries of which, the respective end portions of the casings 4 and 6 bear.

Longitudinal apertures 26 are Aformed centrally through said inner sections of the end fittings to accommodate a rod 27 which extends centrally through the interior of the heating tube 2. The aforesaid outer section or cap 13 is lxedly attached to one end of the longitudinal rod the other end of which is screw threaded as at 28 and projects through the cap l14 at the adjacent end of the heater. The last mentioned end portion of the rod 27 is preferably of tubular formation for a purpose hereinafter mentioned. A nut 29 is provided on the screw threaded end of the rod 27 whereby the end fittings may be contracted or drawn together, so that the respective ends of the heating tube 2 and the casings 4 and 6 are forced into leak proof engagement with the jointing rings or washers 21 and 22. Similar jointing rings or washers may be interposed between the respective inner sections l16 and 17 and their caps 13 and 14.

The inner section or cap 16 may have a number of longitudinal ports or passages 31 formed therein in order to establish communication between the aforesaid annular space or passage 9 and a chamber 32 which is formed between the said 'inner section 16 and its cap 13.

The portion of the longitudinalrod 27 accommodated within the inner section 16 is reduced in cross sectional larea, preferably by the formation of flats 33 around its periphery to thereby permit the Water to pass between the rod 27 and the aperture 26 in the inner section 16, into the internal passageway 11 of the heating tube. The opp0- site end portion of the longitudinal rod 27 is preferably of tubular formation as at 27 and communication lnay be established between the interior 11 of the heating tube and the said tubular portion 27 by way of orifices 36 formed in said rod adjacent the inner extremity of the tubular` portion thereof. The tubular portion 27u which is externally threaded as aforesaid, thus serves as a nipple to which a hot Water delivery pipe or the like may be connected. The opposite end portions of the resistance wire 3 may pass through apertures formed in the inner sections 16 and 17 of the end fittings and are provided with, or led to, suitable terminals (not shown).

In operation the water enters the heater through the opening 7 in the outer casing 6 and ows along the annular space 9 through the ports 31 in the inner section 16 of the appropriate end fitting into the chamber 32, and thence through the passage between the reduced portion of the longitudinal rod 27 and the aperture 26 in the section 16 into the internal passage 11 of the heating tube, and finally by Way of the orifices 36 into the tubular portion of the rod 27 from which it ma be drawn off as required.

uring its passage through the heater the water is continuously heated and owing to the relatively large heating surfaces pro vided by the heating tube and the surrounding casings 4 and 6 and the relatively small cross sectional area of the water circulating passage 9 and 11 a high rate of thermal etliciency'is obtained.

Having now described my invention what I claim as new and desire to secure by Letters Patent is: 1. An electric water heater including opposing fittings, a rod i connecting said fittings, a tubular element surrounding and spaced from the rod and forming therewith a water passage, an electric resistance element wound directly upon the tubular element, a casing surrounding the tubular ele- 8' ment and spaced therefrom, the fittings closing theA space between said tubular element andcasing against the passage of water, and a, second casing surrounding and spaced from the first mentioned casing to define a water passage between said casings.

2. An electric water heater comprising a tubular heating element adapted for the passage of liquid therethrough, an electric resistance on the exterior of said element, cylindrical casings arranged around and spaced from said heating element to form. an annular water circulating passage which surrounds and is isolated from said electric resistance, end fittings adapted to close the ends of said cylindrical casings and establish communication between adyacent ends of said annular passage and the internal passage through the tubular heating element, a rod extending longitudinally of the heating element, and means associated with Said rod to retain the heating element and said casings in proper spaced relationship and in leak proof engagement with said end fittings for the purpose set forth.

3. An electric water heater comprising a. tubular heating element adapted for the passage of liquid therethrough, an electric resistance wound upon the exterior of said tubular element, cylindrical casings arranged concentrically around said heating element to thereby form an annular water circulating passage which surrounds and is isolated from said electric resistance, end fittings adapted to close the ends of said cylindrical casings, one of said endk fittings having longitudinal ports or passages therethrough to establish communication between adjacent ends of said annular passage and the internal passage through the heating 1 element, and means for clamping said heating element and casings in proper concentric relationship between said end fittings.

4. electric water heater comprising in comb1nat1on a tubularv .aheating "element l adapted for' the passage of liquid. through, anelectric woundonth exterior of said tubular elemen, casin s 'arranged concentri spa relationship around slid tings adapted to close the ends of said'cyliudrical casings, a cap memberattached to one of said end fittings, said cap member forniing a chamber which communicates with the' adjacent ends of said` annula'rpassage and the interior of the heatingelement b fment and said casings.

5. An eloetricwater heat-'er comprising a tubular heating element of heat refractory materia adapted for the passage of liquid gtherethrou h, an electric resistance on the exterior o said element, cylindrical casings i arranged around said heating element to thereby forni an annular water circulatnif passage which surrounds and is isolated from said electric resistance, end fittings adapted to close the ends of said cylindrical casings, one of said end fittings having ports or passa' to establish communication between a jacent ends of said annular.

l Leagues md; maid! tislaff ment to thereby form an annular watercirf'; culating passage which surrounds and is lated from said electric resistance, end fitr" `and the internal passage ofthe heatiug ,e ement, exiblejointing rings seated fon-the .inner faces of said end'iittings and t'o form water tight 'oints' between. sai lfiittings and the ends o said casings,`

and means for drawin said jointin'g rings against the ends of sai .casings 6. An electric water heater comprising a tubular heating element ada ted for the passag'eofliquid therethroug an electric resistance mounted on the exterior of said clement, cylindrical casinos arranged around said heating element to thereby form an annular water circulating passage which surrounds and is isolated from said electric rej sistance, end fittings adapted to close the .ends of said casings, one of said end fittings having ports or assages therein to establish communication tween adjacent ends of said annular passage and the internal asu sage of the heating element, a rod extending longitudinally and centrally through the tubular heating element, said rod having a hollow end portion in communicationwlth said internal assage of the heating element whereby the cated liquid is delivered from the heater, and means associated with said rod whereby said endv fittings ma be drawn into leak proof en agement wit the adjalcent ends' of said eating element and casmss 1n testimony whereof I atlix my signature. irnos. H. MCQUINN. i 

